IAMBIC. An Iamb or Iambus is a metrical foot consisting of a short and a long syllable—as bĕfōre ; or as Coleridge[1] gives it,

'Ĭāmbĭcs mārch frŏm shōrt tŏ lōng.'

{ \override Score.TimeSignature #'stencil = ##f \key d \major \partial 8 \clef bass \relative d { \autoBeamOff d8 a'4 r8 d cis4 r8 cis d a fis d a'4 } \addlyrics { Re -- venge! re -- venge! re -- venge! Ti -- mo -- theues cries } }

This, from Handel's Alexander's Feast, is an iambic passage. So also is 'Rejoice greatly' from the Messiah. So is the following from the Finale to Beethoven's Kreutzer Sonata' (op. 47).

{ \override Score.TimeSignature #'stencil = ##f \time 6/8 \key a \major \override Score.Rest #'style = #'classical \relative b' { r4 b8-. b4-. dis8-. | e4\sf b8-. b4-. dis8-. | e4\ff \repeat unfold 6 { dis8( e4-.)\sf } d!8( cis4-.) b8( | a4) } }
etc.
[ G. ]
  1. 'Metrical feet-Lesson for a boy.' Poetical Works. 11 145.